1. Field of the Invention
The present invention relates to a remote control device which enables, for example, a door unlocking operation for automobiles to be performed, and more particularly, to a remote control device which enables a remote control operation to be automatically executed by the user's approaching an object to be remotely controlled, such as an automobile .
2. Description of the Related Art
In recent years, practical use of the remote control devices for automobiles has begun . This remote control device is operated in the manner described below: the user of the automobile carries; a small transmitter with him or her. When he or she depresses, for example, a door unlocking button provided on the transmitter near the automobile, the transmitter transmits a FM modulated signal containing identification information and command information. A receiver provided on the automobile decodes the signal transmitted from the transmitter, and outputs an execution signal on the command information to an execution portion when coincidence of the identification information is obtained. Thus, the door is unlocked by an operation mechanism in the execution portion.
However, in the aforementioned remote control device, the user who carries the transmitter must be within a distance where the transmission signal can reach the receiver loaded on the automobile or the like when he or she depresses the operation button. Thus, the user must always keep the distance to the automobile or the like in mind.
Also, when the user tries to use the transmitter at a distance close enough to the automobile with baggages in his or her both hands, he or she must let go of the baggages in the hands temporarily and operate the transmitter. This is inconvenient.